1. Field of the Invention
The present invention relates generally to rupturable fluid flow indicators, and more particularly, to such indicators used in conjunction with rupture disks to indicate rupture.
2. Description of the Prior Art
Safety pressure relief apparatus of the rupturable type are often utilized in applications where an indication of the operation of the apparatus is desirable or necessary. For example, in plants for carrying out chemical processes, when a rupturable pressure relief apparatus ruptures and relieves pressurized fluid from a vessel or system, it is generally necessary to shut down a portion of the plant or to take some other immediate corrective action. Accordingly, an alarm or other immediate indication of the operation of the pressure relief apparatus is highly desirable.
Fluid pressure rupturable apparatus generally include one or more rupture disks sealingly clamped between annular supporting members which are bolted together or which are clamped between bolted flanges. Thus, when a rupture disk ruptures as a result of excessive fluid pressure, or when the rupture disk fails for any other reason, an indication of the rupture or failure may not be given other than by the resulting change in the pressure condition of the vessel or system being protected. In certain situations, the pressure condition of the vessel or system will not change appreciably whereby the rupture or failure of the rupture disk will go unnoticed for some period of time causing undesirable results.
Rupture disk monitoring devices and rupture disk alarm systems have been developed and utilized heretofore. For example, U.S. Pat. No. 3,770,918 issued Nov. 6, 1979 is directed to a monitoring device for a reversible rupture disk which includes electric probes positioned in the space behind the rupture disk. U.S. Pat. No. 4,342,988 issued Aug. 3, 1982 is directed to a rupture disk alarm system which includes a signal carrying means in touching relationship with the rupture disk which is altered by movement of the rupture disk. U.S. Pat. No. 4,408,194 issued Oct. 4, 1983 is directed to a rupture disk monitor which includes capacitor means positioned in spaced relationship to the rupture disk to sense the operation of the rupture disk.
While the prior art rupture disk monitoring devices and systems have achieved varying degrees of success, they generally are not suitable or reliable in high temperature and/or highly corrosive applications and do not operate consistently unless full opening of the rupture disk occurs. Other problems which are encountered with various ones of the prior art devices include the shearing of the electric current conductor wires or strips by the rupture disk supporting flanges, the corrosion of the wires or strips by the fluids involved, the breaking or damaging of the device when handled and installed and other similar problems.
By the present invention an improved rupturable fluid flow indicator is provided which can be utilized to indicate the operation or failure of a rupture disk and which obviates the various problems mentioned above.